Gearing.



E. A. JEFFREYS & W. B. SAYBRS.

Patented Apr. 27, 1909.

7 BHEETfl-SHEET 1.

E. A. JEFFREYS & W. B. SAYERS.

GEARING. APPLICATION FILED MAR. 6, 190a.

Patented Apr. 27, 1909.

7 SHEETSSHEET 2.

E. A. JEFFREYS & W, B. SAYERS.

GEARING.

APPLICATION FILED MAR. 6, 19 08.

9 1 9, 359. Patented Apr. 27, 1909.

7 SHEETS-SHEET 3.

B. A. JEFFREYS & W. B. SAYERS.

GEARING.

APPLIOATION FILED MAIL-6, 1908.

Patented 27, 1909. S-SHEET 4.

Apr.

7 SHEET E. A. JEFPRBYS &: W. B. SAYERS.

GEARING.

APPLIOATION FILED MAR. 6, 190B.

Patented Apr. 27, 1909.

'1 SHEETS-SHEET 5.

7 SHEETS-SHEET 6.

Patented Apr. 27, 1909.

GEARING.

E. A. JEPFREYS 9 W'. B. SAYERS..

APPLICATION FILED MAE. 6, 1908.

Q M. q

UNITED s'rAfrns raann'r OFFICE.

EDWARD AUGUSTUS JEFFREYS AND WILLIAM BROOKS SAYERS, OF GLASGOW, SCOTLAND.

I GEARING.

Specification of Letters Patent.

Application filed Hatch 6,

Patented April 27, 1909.

1908. Serial No. 419,489.

To all 'ulwm it may con-corn:

Be it known that we, Rowan!) Auot s'rus Jl-zr'r'mars and \ViLLiAM. Bnoons bAYnlts, subjects of the King of (treat Britain and Irea land. residing, respectively, at Glasgow, in .the county of llanark, Scotland, have invented Improved Gearing, of which the following is a specification.

This invention relates to epicyclic driving 1 i mechanismof a general type now well known in various forms, embodying an externally toothed mcn'iber driven eccentric-ally by the prime mover in relation to an internally toothed member connected to or forming part. of the driven body or bodies and serving in its simplest form as a speed reducing gear, and in other forms as variable speed changing and reversing gear the driving and driven bodies in either case being able to ex- :9 change functions when required.

llitherto in mechanism of this character the eccentrieally driven member has been constrained to move without rotation about its own'axis in various ways, none of which however are entirely successful for various reasons. Thus a speed reduction gear has been proposed in which the desired eccentricity and constraint are derived by the employment of pins upon one member which 0 extend within circular holes of considerably larger diameter in the other member, there being a consequent.- eccentric motion between such pins and the holes aforesaid as the eccentrically driven member operates. \Vith such an arrangement however any wear or slackness which may occur or exist between the eccentrically driven member and the eccentric which effects the drive, Will result in play between the pins and holes afore- 40 said and cause objectionable knocking or hammering.

Now the object of the present invention is to avoid in mechanism opera-ting similarly to that above referred to, the foregoing disisfatlvantage by connecting the toothed memsiiber, which is to be. driven eccentrically, to a ncrnber which may be either a non-revoluble member or a member adapted to be used se-tl j .stationarily or while revolving at ,ill,= y cranks, crank links or eccentricsof such 'a character, as hereinafter described that the eccentricity of motion ofthe toothed member with respect to the other memberis unaffected by wear of, or looseness at, the

driving eccentric.

in the accompanying drawings, Figure 1 is a central longitudinal section of a gear arrangement capable of producing three forward speeds and reversal at another speed. Figs. 2, 3 and '-.l: are cross sections taken respectively on the lines A B, C-- D and E l of Fig. 1, Figs. 2and 3 bein viewed in the direction of the arrow 3 and Fig. 4 in the direction of the arrow as. Fig. Sis a view similar to Fig. 1 illustrating a modified construction. l ig's. 6 and T are views likewise similar to Fig. 1 illustrating two forms of gear for obtaining four forward speeds and reversal at another speed.

absolutely true but more or less conventional to illustrate the features clearly as will be. obvious by comparison of the views.

Referring first to Figs. 1 to l of the drawings a is the engine shaft which is supported in any convenienttype of bearings.

crank 1) upon which is carried by ball bearings c a sleeve (Z consisting in part of the ring d. The said sleeve d is connected as by cranks 0, having a throw equal to thatof the crank b, to a wheel f which is revoluble upon the reduced portion 9 of the hub of a second wheel g itself revoluble upon the en ine. shaft (4. As shown, the wheel f revo ves on a roller bearing f and the wheel 9 upon roller bearings g". The pins 0 of the cranks e which may conveniently be three in number revolve in recesses d spaced cquidistantlv around the ring (1*, the pins 0 of the cranks revolving similarly in ap )ropriately bored bosses f on the wheel f'. If desired the crank and cranks or either of them can be counterweighted as indicated in dot and dash lines at b and c" Fi 1. 71. is the power sleeve or shaft, which in addition tobeing carried in any appropriate bearing or bearings, not shown, may be supported as by a ball bearing k upon the engine shaft a, or serve as a support for such shaft. if is a wheel rin or flange upon the sleeve or shaft it, upon w ich is rcvolubly mounted an annular member or wheel a. being retained in position thereon by the flange portion 2" and the cover ring 11. It is to be understood that brake straps, bands or any other suitable device or means will be employed in conjunction with the revoluble members f, g andi for the urpose of arresting any of the same at wi l as In Figs. 1, 5, 6 and 7 the sections are not;

not shown, and formed or provided with ais usual in many similar gears but which being therefore well known are not'here illustrated. Further for the sake of simplicity in understandin the description relatin I to the speeds deriva le by-the gear, as herea er set forth, the gear wheels now to be referred to will be designated by numerals corresponding to the number of teeth of the several. wheels, without intention however of being limited in any way to such numbers.

. The sleeve d, according tothe example, is

upon the wheel 2', and, on the ring 03 an in provided with an external ring of teeth 50 engaging an internal ring of teeth 70 upon the wheel rim k an external ring of teeth 38 engaging an internal 'ring of teeth '58 rotation about its own axis, in a path concentric with the engine shaft. Hence the power sleeve or shaft 7:. is rotated by the engaged toothed rings 50, 70, at each revolution of the engine shaft, by an amount equal to' the difference betweenv the numbers of teeth aforesaid viz. 20 so that if the speed of the engine shaft be 800 revolutions per minute the power sleeve or shaft II. will be driven 230 revolutions per minute roughly. Under these conditions the wheel rim i revolved by engaged toothed rings 38 "58 overruns the wheel rim [1. and the wheel 9 is rotated in a backward direction by the engaged, toothed rings 50, 30. If now the wheel f be liberated and the wheel 9 be held stationar in lieu thereof, the sleeve (1 will be cause to revolve about its own axis in addition to travelin in the path of the engine shaft crank b but at a speed less than that of the engine shaft determined by the toothed rings 50, 30 that is to say equal to the difference in number of their teeth so .that the revolutions per minute compared with the speed of the engine shaft a will be 320 revolutions per minute which modified in the ratio of 4H} is reduced to 230 and added to the speed'of the sleeve el around the crank centers lmpa-rts a resultant speed of 550 revolutions approximately per minute tothe power sleeve or shaft For backward rotation the wheel rim 5- is held stationary and the wheels f and g are liberated, in which case the sleeve (Z will be revolved negatively about its own axis at a speed of 420 approximately but this speed is reduced by the toothed rings 50 and to 300 approximately from which however-has to be deducted thespeed, viz., about 230, at which the toothed rin' 70 would have been driven forward had't l6 sleeve 11 been stationary, thus causing the power sleeve h to rotate backward at the speed corresponding to the difference between the two, or 70 revo-- lutions per minute approximately.

Flg. 5 illustrates a modified construction of gearing, similar to that ust descr1bed,'1n

which the crank b is formed in one with the engine shaft (1. The portion a of the shaft a 1s reduced in diameter and the web 6 turned to a diameter corresponding to the means the ball bearings 0 can be easily placed in position, the cut away part of the web 6 being occupied by aportion b of the plate I) carrying the balance weight b. In this example the toothed rings corresponding to the rings already fully described are assumed to have teeth agreeing in number with the numerals respectively applied thereto. The through drive or highest speed of the power sleeve or shaft h is derivable by clutching the wheel 5;, as by a member 7', to the shaft a, when the teeth 24 will cause the sleeve d to revolve with the shaft a and consequently positivel rotate the sleeve or shaft h without sli T e-cranks e of Fig. 1 have been replace by links is or knuckles revoluble on stationary pins 0 e' secured respectively to the ring d and wheel f.

Fig. 6 shows a form of gearing for enabling four forward speeds to he obtained as well as a single backward speed. According to it the sleeve (2 is rovided with an additional ring of externa teeth referred to as 66 enga ing an internal ring of teeth 90 in a supp ementary wheel 1):. As in the first described case, retention of the wheel f will produce a certain reduced speed of the sleeve or shaft h as compared with that of the engine shaft a, while liberation of such wheel and retention of the wheel g will produce a speed which more nearly approaches that of the shaft a. If the wheel at be held stationary and the wheels f and g be both free to revolve a speed less than either of the s eeds referred to can be secured and may e utilized as the first speed, that is to say the sleeve at will be rotated negatively about its own axis by the engaged toothed rings 66, 90 and in this way diminish, by approximately one half, the speed of the sleeve orshaft h which would have resulted from the toothed rings 32, 56 had the sleeve d been prevented from revolvin by means of the'cranks e as is insured by olding the wheel f stationary. The action of the gear,-

ing in other respects is the same as described with regard to Fig. 1, the difference residmg 1n the altered gear ratios as is lndl- 'cated.

Fig. 7 illustrates another modification in which the. supplemental wheel m when held stationary is arranged to produce a speed between that obtainable by holdin the wheel stationary and full speed. nthis case the supplemental wheel m controls asupplemental tt t'llll'l('illl driven sleeve n. fitted with an external ring of teeth H: engaging an internal ring of teeth carried by the wheel This sleeve n is constrained in its movement by eccentrics c (as is also the sleeve oi) connected with the wheel in and, like the sleeve 'rl 'is operated by an eccentric u, instead oi. by a crank. As will be appreciated the speeds derived by holding the wheels f and will be similar to those previously described except in so far as the gear ratios indicated di flier therefrom. \Vhen the wheel m is held. however, the sleeve '11 will. without.revolving about its own axis, rotate the wheel through the toothed rings it. (it) which in turn will cause the wheel 7' and sleeve lo to be rotated at a speed greater than tlmtimparted to the same while the. wheel was stationary and thus further increase the speed. In like manner the range and number of speeds obtainable can be increased by employing a greater number of cccentrically dr ven sleeves or members. of the special character referred to with appropriate revoluble wheels and toothed rings. the speed derived in some cases being even greater than that of the through drive. The balancing of the eccentrics c can be readily effected by thickenin the metal at r'- as indicated in dot and das lines.

Although the. wheel f carrying the cranks, crank links r' or eccentrics c are shown in l igs. ti and T with plain cylindrical bearings it will be understood that the same may be arranged to. run on roller bearings as in Fig. 1 or on ball bearings as shown in Fig. 5.

The improved gearing is of 'a very compact construction and convenient in form.

'hatwe claim is:--

l. i lpicyclic driving mechanism comprising a shaft an internally toothed wheel carried thereby, an internally toothed wheel revolnblc upon the. exterior of the first internally toothed wheel and adapted to be held stationary at will, an externally toothed sleeve engaging both of said wheels, means for tt't'tllllflt'tl'lly driving said sleeve, a wheel adapted to be held stationaryor to revolve at will and means connecting the externally toothed sleeve to the last named wheel soheld stationary at will, an externally toothed sleeve engaging, both of said wheels, means for eecentrieally driving said sleeve, a wheel adapted to beheld stationary or to revolve at. will and counterbalancedmeans connecting the externally toothed sleeve to the lastnained' wheel so thatgwhcn the latter is stationat' the sleeve is positively constrained to its correct. eccentric path independently of its dri\ ing means.

3. 'Epicyclic driving mechanism comprising a shaft an internally toothed wheel carried thereby, an internally toothed wheel ,revolul'ile upon'the exterior of the first internally toothed wheel and adapted to he held statiolmry at will, an externally toothed sleeve engaging both of said wheels, means for eccentrically driving said sleeve, a wheel adapted to be held stationary or to revolve at will and eccentrics (.Ol'lIlGCtlllg the externally toothed sleeve to the last named wheel so that when the latter is stationary, the. sleeve is positively constrained to its correct eccentric path independently of its driving "103115.

lipicyclic driving mechanism comprising a shaft an internally toothed wheel carried thereby, an internally toothed wheel rcvoluble upon the exterior of the first internally toothed wheel and adapted to be held stationary at will, an externally toothed sleeve engaging both of said wheels, means for ecccntrieally driving said sleeve, a wheel adapted to be held stationary or to revolve at will and counterlnilanctal eccentrics connecting the externally toothed sleeve to the. last named wheel so that when the latter is stationary, the sleeve is positively con-' strained to its correct eccentric pendeut'ly of its driving means.

.lflpicyelic driving mechanism, comprising a shaft an internally toothed Wheel carpat-h inde- 'ried thereby, an externally and internally toothed sleeve exteriorly engaging the said wheel, a motor shaft having means for ecccntrically driving said sleeve, a Wheel adapted to be held stationary or to revolve at will upon the motor shaft and having an external ring of teeth engaging the toothed interior of the cccentrically driven sleeve, a wheel adapted to be held stationary or to revolve alternatively with the lastnamed wheel and mounted on the hub of said wheel, and means connecting the toothed sleeve to the la t named .wheel so that when the latter is stationary the sleeve is positively constrained to its corre t eccentric path independently at it; driving means on the motor shaft.

(3. l lpicyelic driving mechanism, comprising a shaft an internally toothed wheel carried thereby, an externally and internally toothed sleeve exteriorly engaging the said wheel, a motor shaft havin' means for eccentrieally driving said s cove. a wheel adapted to he held stationary or to revolveat will upon the motor shaft: and having an external ring of teeth engaging the toothed interior of the eccentrically driven sleeve, a

wheel adapted to be held stationary or to revolve alternatively with the last named wheel and mounted on the hub of said wheel, and counterbalanced means connecting the toothed sleeve to the last named wheel so'that when the latter is stationary the sleeve is positively constrained to its correct eccentric. path independently of its,

e ternally driving means on themotor shaft.

71 Epic clic driving mech'amsm, comprising a sha an internally toothed wheel carriedthereby, an externally and internally toothed sleeve exteriorly engaging the said wheel, a motor shaft having means for 'eccentrically driving said sleeve, a wheel adapted to be held stationary" or to revolve at will upon the motor shaft and having an external ring of teeth engaging the toothed interior of the eccentrically driven sleeve, a

wheel adapted to be held stationary or to.

revolve alternatively with the last named wheel and mounted on the hub of said wheel, and eccentrics connecting the toothed sleeve to the last named wheel so that when the latter is stationary the sleeve is positively constrained to itscorrect-eccentric path in dependently of its driving. meanson the motor shaft. I

S. Epicyclic driving mechanism,- compris-' ing a shaft an internally toothed wheel carried thereby, an externally and internally toothed sleeve exteriorly engaging the said wheel, a motor shaft having means for eccentrically driving said sleeve, a wheeladapted to be held stationary or to revolve at will upon the motor shaft and having an external ring of teethengagingthe toothed interior of the eccentricallydri'ven sleeve, a wheel adapted to be held stationary or to revolve alternatively wit-h the last named-wheel and mounted on the hub of said wheel, and counterbalanced eccentrics connecting the toothed sleeve to .the'last named wheel so that when the latter is stationary the sleeve is positively constrained to its correct eccentric path independently of its driving means on the motor shaft.

9. Epicyclic driving mechanism, comprising' a shaft an internally toothed wheel carried thereby, an internally toothed wheel revoluble upon the exterior of the first internally toothed wheel and adapted to be held stationary at will, an externally and internally toothed sleeve exteriorly engaging the said Wheels, a motor shaft having means for eccentrically driving said sleeve, a wheel adapted to be held stationary or to revolve at will upon the motor shaftand having an external ring of teeth engaging the toothed interior of. the eccentrically driven sleeve, a wheeladaptcd to be held stationary or to revolve alternatively with the last named is stationary the sleeve is positively constrained to its correct eccentric path independently of itsdriving means on the motor shaft.

10. Epic clic driving mechanism, 'comprisin a s aft an internally toothed wheel carried thereby, an internally toothed wheel revolubl upon the exterior of the first intoothed wheel and adapted to be held stationary at will, an'externally and internally toothed sleeve-exteriorly engaging the said'wheels, a motor shaft having means for eccentricall' driving said sleeve, a wheel adapted to be? eld stationary or to revolve at will upon themotor shaft and having an external rin of teeth engaging the toothed interior of t e eccentrically driven sleeve, a wheel adapted to be held stationary or to revolve alternatively ,with the last named wheel and mounted on the hub of said wheel, and counterbalanced means connecting the toothedsleeve "to the last named wheel so that when the latter is stationary the sleeve is positively constrained to its correct eccentricpath independently of its driving means on' the motor shaft.

11. Epicyclic driving mechanism, comprising a shaftan'internally' toothed wheel carried thereby, an internally toothed wheel revoluble-uponethe exterior of the first internally toothed wheel and adapted to be held stationary at will, an externally and internally toothed sleeve exteriorly engaging the said wheels, a motor shaft having means for eccentricall driving said sleeve, a wheel adapted to be eld'stationary or tor-evolve at will upon the motorf shaft and having an external ring of teeth engaging the toothed interior of theeccentrically driven sleeve, a wheel adaptedi'tobe held stationary or to revolve alternatively with the last named wheel and mountedon the hub of said wheel, and eccentrics connecting the toothed sleeve to the last named wheel so that when the latter is stationary the sleeve is positively constrained to its correct eccentric path independently of its driving means on the motor shaft.

12. Epicyclic driving mechanism, comprising a shaft an internally toothed wheel carried thereby, an internally toothed wheel revoluble upon the exterior of the first internally toothed wheel and adapted to be held stationary at will, an externally and internally. toothed sleeve exteriorly engaging the said wheels, a motor shaft having means for eccentrically driving said sleeve, a wheel adapted to be held stationary or to revolve at will upon the motor shaft and having an external ring of teeth engaging the toothed interior of the eccentrically-driven sleeve, a wheel adapted to be held stationary or to revolve alternatively with the last named Wheel and mounted on the hub of said wheel, and counterbalanced eccentrics connecting slam is positively constrained to itscorrect eccenring of teeth of the trio path inde endently of its driving means on the motor iaft.

13. .Epicyclic driving mechanism, comprising a shaft an internallytoothcd wheel carried thereby, an externally and internally toothed sleeve exteriorly engaging the said wheel, a motor shaft having means for eccent-rically driving said sleeve, a wheel adapted to he held stationary or to revolve at will upon the motor shaft andhaving an external rm of teeth en aging the toothed interior of time eccentrica l ly driven sleeve and an independent ring of internal teeth, a wheel adapted to be held stationary or to revolve alternatively with the last named wheel and mounted on the hub of said wheel, a toothed sleeve exteriorly engaging the independent second named wheel, a wheel adapted to be held stationary or to revolve at will upon the motor shaft located 4 adjacent to the said toothed sleeve, and

means connecting the first-named toothed sleeve to the second named wheel and the last named toothed sleeve to the last named wheel so that when either of said wheels is held stationary the corresponding sleeve is positively constrained to its correct eccentric path independently of its driving means on the motor shaft. 1 a

14. Epicyclic driving mechanism, comprisin a shaft an internally toothed wheel carrie thereby, an externally and internally toothed sleeve exteriorly engaging the said wheel, a motor shaft having means for eccentrically driving said sleeve, a wheel adapted to be held stationary or to revolve at will upon the motor shaft and having an external ring of teeth engaging the toothed interior of the eccentrically driven sleeve and an independent rin of internal teeth, a wheel adapted to be lield stationary or to revolve alternatively with the last named Wheel and mounted on the hub of said Wheel, a toothed sleeve exteriorly engaging the independent ring of teeth of the second namedwheel, a wheel adapted to be held stationary or to revolve at will upon the motor shaft located adjacent to the said toothed sleeve, and counterbalanced means connecting the first named toothed sleeve to the second named wheel and the last named toothed sleeve to the last named wheel so that when either of said wheels is held stationary the corresponding sleeve ispositively constrained to its correct eccentric path independently of its driving means on the motor shaft.

.15. 'Epicyclic driving mechanism, comprising a shaft an interna 1y toothed wheel carried thereby, an externally and internally toothed sleeve exteriorly engaging the said wheel, a motor shaft having means for eccentrically driving said sleeve, :1 wheel adapted the toothed sleeve to the'last named wheel so i to be he d statia a or to revolve at 1w!!! .upon themeton'sha t and having an external ring ofteeth engaging the toothed interimof the eccentrically driven sleeve and an independent ring of internal teeth, a wheel adapted to be held stationary or to revolve alternatively with the last named wheel and mounted on the hub of said wheel, a toothed sleeve exteriorly engaging the independent ring ofteeth of the second named wheel, a wheel adapted to be held stationary or to revolve at will upon the motor shaft located adjacent to the said toothed sleeve, and eccentrics connecting the first named toothed sleeve to the second named wheel and the last named toothed sleeve to the last named wheel so that when either of said wheels is.

held stationary the corresponding sleeve is positively constrained to its correct eccentric path independently of its driving means on the motor shaft.

16. ,Epicyclio driving mechanism, comprising a shaft an interna ly toothed wheel carried thereby, an externally and internally toothed sleeve exteriorly engaging the said wheel, a motor shaft having means for eccentrically driving said sleeve, a wheel adapted to be held stationary or to revolve at will upon the motor shaft and having an external ring of teeth engaging the toothed interior of the eccentrically driven sleeve and an independent ring of internal teeth, a wheel adapted to be held stationary or to revolve alternatively with the last named Wheel and mounted on the hub of said wheel, a toothed sleeve exteriorly engaging the independent ring of teeth of the second named wheel, a wheel adapted to be held stationary or to revolve at will upon the motor shaft located adj acont to the said toothed sleeve, and counterbalanced eccentrics connecting the first named toothed sleeve to the second named wheel and the last named toothed sleeve to the last named wheel so that when either of said wheels is held stationary the corresponding sleeve is positively constrained to its correct eccentric path indepenlently of its driving means on themotor sha t.

17. Epi cyclic driving mechanism, comprising a shaft an internally toothed wheel carried thereby, an internally toothed wheel revoluble upon the exterior of the first internally toothed wheel and adapted to be held stationary at will, an externally and internally toothed sleeve exteriorly engaging the said wheels, a motor shaft having means for eccentrically driving said sleeve, a wheel adapted to be held stationary or to revolve at will upon themotor shaft and having an external ring of teeth engaging the toothed interior of the eccentrically driven sleeve and an independent rim of internal teeth, a wheel adapted to be hel stationary or to revolve alternatively with the last named 1 dependent ring of teeth the second named first. named toothed sleeve to. the second corresponding sleeve is positively constrained nally toothed sleeve exteriorly engaging the said wheels, a motor shaft having means for eccentrically driving said sleeve, a wheel adapted to be held stationary or to revolve veccentrically driving said sleeve, a Wheel adapted to be held stationary-or to revolve external ring of teeth engaging the toothed dependent ring of teeth of the second named \vheeil and mounted on the hub of said wheel, a toothed sleeve exteriorl engaging the mwheel, a wheel adapted to he held stationary or to revolve at will upon the motor sha located adjacent to the said toothed sleeve, and means connecting the first named toothed sleeve to the second named wheel and the last uamed'toothed sleeve to the last named wheel so that when either of said wheels is held stationary the corresponding sleeve is positively constrained to its correct eccentric path independently of its driving means on the motor shaft.

18. Epicyclic drivin mechanism, comprising a shaftan internally toothed wheel carried thereby, an internally toothed wheel revoluhle upon the exterior of the first internally toothed wheel and adapted to be held stationary at will, an externally and internally toothed sleeve exteriorlyengaging the said wheels, a motor shaft having means for at will upon the motor shaft'and having an interior of the eccentrically driven sleeve and an independent ring of internal teeth, a wheel adapted to he held stationary or to revolve alternatively with the last named wheel and mounted on the hub of said wheel, a. toothed sleeve exteriorly engaging the inwheel, a wheel adapted to be held stationai I or to revolve at will upon the motor shafl; located adjacent to the said toothed sleeve, and counterbalanced means connecting the named Wheel and the last named toothed sleeve to the last named wheel so that when either of said wheels is held stationary the to its correct eccentric path independently of its "driving means on the motor shaft.

19. Epicyclic driving mechanism, comprising a shaft an internally toothed wheel carried thereby, an internally toothed wheel revoluhle upon the exterior of the first int-ernally toothed wheel and adapted to be held stationary at will, an externally and interat will upon the motor shaft and having .an external ring of teeth engaging the toothed 1 =ing a shaft an interna interior of the eccentrically driven sleeve and an independent ring of internal teeth, a Wheel adapted to be held stationary or to revolve alternatively with the last named wheel and mounted on the hub of said wheel, a toothed sleeve exteriorly engaging the independent ring of teeth of the second named wheel, a wheel adapted to be held stationary or to revolve at will upon the motor shaft located adjacent to the said toothed sleeve, and eccentrics connecting the first named toothed sleeve to the second named wheel and the last named .toothed sleeve to the last named wheel so that when either of said wheels is held stationary the corresponding sleeve is positively constrained to its correct .means on the motor shaft.

20. Epicyclic drivin j mechanism, comprisllytoothe'd wheel car ried thereby, anv internally toothed wheel revoluble upon'the exterior of the first-internally toothed Wheel and adapted to be held statlonaryat will, an externally and internally toothed sleeve exteriorly engaging the said wheels, a motor shaft having means for eceent-rically driving said sleeve, a wheel adapted to be held statlonary or to revolve at will upon the motor shaft and having an external rin of teeth en aging the toothed interior of t 1e eccentrical y driven sleeve an independent ring'of internal teeth, a wheel adapted to be held stationary or to revolve alternatively with the last named wheel and mounted on the hub of said wheel, a toothed sleeve.;exteriorly engaging the independentri'ng of teeth of the second named wheel, a wheeladapted to beheld stationary or to revolve" at will upon the motor shaft located adjacent to the said toothed sleeve, and counterbala-nced. eccentrics connecting the first named; toothed. sleeve to the second named wheel and the last namedtoothed sleeve to .the last named wheel so that when either of animal) nieusrus Jiaraias.

WILLIAM BROOKS SAYERS.

Witnesses:

ALFRED MIDDLETON, Ronmrr- A, -Tno wson. 

